1. Field of the Invention
This invention relates generally to the deployment of inflatable structures, and more particularly to an arrangement for deployment of evacuation slides or life rafts associated with aircraft.
2. Description of the Related Art
Inflatable evacuation slides and/or slide rafts provide a rapid means for evacuating passengers and flight personnel in the event of an emergency. In commercial aircraft, the slides are normally stored uninflated in a container mounted on the interior of the aircraft door or immediately adjacent thereto. With the door closed, a girt bar is connected to brackets on the floor inside the doorway such that it is only necessary to open the door to automatically deploy the slide in the event of an emergency evacuation. When the door is opened, the girt bar normally pulls the slide through the doorway until gravity can take effect to unfold or unroll the slide outside of the doorway. Once outside the doorway, the slide or slide/raft is rapidly inflated through the application of fluid pressure.
In military applications, inflatable life rafts and their deployment systems are sometimes located in wing compartments of the aircraft. This is often necessary to maximize space in the fuselage for transporting equipment, supplies and personnel. A pair of life rafts and the deployment systems associated therewith may be located within a special compartment situated in each wing. This compartment is formed with a separate chambers for the life raft and the deployment system. In the prior art the deployment system for each life raft includes a container of highly pressurized gas that is located in a bottle chamber adjacent the life raft chamber. Such container includes an inflation valve that is actuable from a remote location, such as the cockpit, by a cable and pulley system routed through the aircraft. When a pull handle or similar device associated with the cable is activated, the valve is opened and the pressurized gas is discharged from the container and into the life raft causing its rapid inflation.
The use of vacuum-sealed inflatable life rafts in the wing compartments of military aircraft, such as the Lockheed Martin C-130 and C-141 aircraft, has become increasingly popular due to their compact size and the protection they afford against water, moisture, fungus growth, and debris. Typically, the container of highly pressurized gas is located in a sealed envelope together with the life raft in the life raft chamber. Consequently, the bottle chamber is no longer utilized.
Similarly, when non vacuum-packed life rafts are provided within the wing compartments, the container with pressurized gas utilized for the deployment of the inflatable structure is also currently repositioned from the bottle chamber into the life raft receiving chamber. This keeps the bottle chamber empty. In both current vacuum-packed and non vacuum-packed applications the cable used to deploy the life raft is typically now routed through both the fairlead assembly and the voided area of the bottle chamber and into the life raft chamber. Such arrangement results in a significant amount of slack in the cable. In some aircraft, the stroke length of the cable for activating the life raft is limited to approximately 3 to 5 inches. Thus, if the slack in the cable exceeds this distance, the life raft cannot be deployed. This problem is augmented in turboprop aircraft, where a large amount of vibration is generated in the wings and in the life raft due to the location of the turbo engines on the wings. Modifications to the aircraft to overcome this problem are usually costly, require a complex procedure of recertification of the aircraft and therefore are undesirable.
Whether the life raft is non-vacuum-packed, vacuum-packed or of any other configuration, it may become necessary to remove the life raft during maintenance procedures. Currently, when a life raft is removed from a wing compartment, the life raft actuating cable must be disengaged from the aircraft cable (that leads from the cockpit to the life raft cable) from underneath the wing of the aircraft. This is accomplished by extending the aircraft""s wing flaps to gain access to the underside of the wing, where a safety wire is removed from a clevis of the aircraft""s cable and a screw connection is removed between the aircraft cable and the life raft cable. Once the aircraft cable and life raft cable are disconnected from each other, the life raft can be removed by unlatching the compartment doors located on top of the wing. Thus, removal of the life raft requires access to both the bottom and top of the wing, resulting in a time-consuming and labor intensive procedure.
It would therefore be desirable to provide an arrangement for reducing the slack and/or vibration in a life raft actuating cable, to thereby assure deployment of the life raft within the required stroke length. It would be further desirable to provide a mechanism for facilitating life raft installation in, and removal from, the wing compartment of an aircraft.
One aspect of the present invention provides an arrangement for deployment of an inflatable structure. The arrangement comprises a container fluidly connectable to the inflatable structure. The container has a pressurized fluid situated therein and a valve movable under force from a closed position while maintaining the pressurized fluid in the container to an open position in which the pressurized fluid is expelled from the container into the inflatable structure for its inflation. The arrangement further comprises a cable guide block having first and second sides, and at least a first conduit extending between the first and second sides. A deployment cable is positioned for guided movement in the first conduit between a rest position and a deployed position. The deployment cable has first and second ends that extend beyond the first and second sides, respectively, with the first end being operably connected to the valve and the second end being accessible for applying a pull force to the deployment cable. With this arrangement, guided movement of the deployment cable in the first conduit from the rest position to the deployed position under the applied pull force causes opening of the valve and inflation of the inflatable structure by the pressurized fluid.
A further aspect of the invention provides an arrangement for deployment of a life raft in an aircraft. The aircraft has left and right wings, a wing compartment located in each wing with a first chamber for receiving the life raft and a second chamber formed independently of the first chamber, and an aircraft cable for remotely actuating the life raft. A life raft is adapted for positioning in the first chamber and a container adapted for positioning in the first chamber with the life raft. The container is fluidly connectable to the life raft and has a compressed fluid situated therein and a valve movable under force from a closed position while maintaining the compressed fluid in the container to an open position in which the compressed fluid is expelled from the container into the life raft for its inflation. The arrangement further comprises a cable guide block that is adapted for positioning in the second chamber. The cable guide block has first and second sides, and at least a first conduit extending between the first and second sides. A deployment cable is positioned for guided movement in the first conduit between a rest position and a deployed position. The deployment cable has first and second ends that extend beyond the first and second sides, respectively, with the first end being operably connected to the valve and the second end being adapted for connection to the aircraft cable for remotely applying a pull force to the deployment cable. With this arrangement, guided movement of the deployment cable in the first conduit from the rest position to the deployed position under the applied pull force causes opening of the valve and inflation of the life raft by the pressurized fluid.
An even further aspect of the invention provides a cable guide block for redirecting a pull force of a cable from a first direction to a second direction. The cable guide block comprises a body having at least first and second sides and at least one tubular member embedded within the body and extending between the first and second sides. The tubular member is shaped to extend along both the first and second directions. A cable is positioned for guided movement in the tubular member. The cable has first and second ends extending beyond the first and second sides, respectively, so that the first cable end extends along the first direction and the second cable end extends along the second direction to thereby redirect a pull force on the cable from the first direction to the second direction.